[Vor. 4 
272 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
Long. cell. 20-35, lat. cell. 8-18 д. 
Paraguay (86). 
Möglicherweise könnte diese kleine Alge zu der Gattung 
Kentrosphaera Borzi gehören. Die Gestalt der Chromato- 
phoren war nicht vóllig zu erkennen. Die Wandverdickung 
des einen Zellendes und die Lebensweise sprechen nicht gegen 
eine solche Ansicht." 
Presumably upon the basis of this last statement, since 
there is no indication of his having seen the plant, Brunn- 
thaler! removes the species to Centrosphaera, publishing it as 
Kentrosphaera gloeophila (Bohlin) Brunnthaler, with the 
original description except that the measurements are given 
as “20-25 y breit, 20-30 р lang." This is apparently an error, 
since the figure published is copied from Bohlin's and is twice 
as long as wide. The habitat is likewise erroneously given 
as В. nidulans. As will be seen from the above original de- 
- scription, what Bohlin actually said was ‘‘in coloniis Rivu- 
lariarum nidulans,’’ thus furnishing a most interesting ex- 
ample of the way in which names creep into the literature, 
as well as emphasizing the necessity of referring to the orig- 
inal in order to get accurate information. 
The cell of what may be regarded as the normal vegetative 
condition of the alga found growing in R. Bornetiana 
measures from 25 to 30 д in diameter, and is practically a per- 
fect sphere. Later on, at the time of spore formation or be- 
cause of the very considerable thickening of the wall and 
ехсгевсепсев which may be formed, the dimensions vary very 
considerably, cells 50х25 д, 70X35 и, and in one instance 
88x40 и having been observed. In the latter case, however, 
exclusive of the thickened wall, the measurements were 
64х25 и. 
There is a single chloroplast which lies close to the wall 
and usually lines the entire cell (pl. 18, figs. 2-4). Occasion- 
ally the chloroplast is incomplete, producing a light spot of 
varying size (pl. 18, fig. 1.) One large and prominent pyre- 
noid is always present, and a single nucleus, either centrally 
or laterally placed, may be made out by staining. At no time, 
1 Brunnthaler, J. Protococcales. In Pascher's Die Süsswasser-Flora Deutsch- 
lands, Osterreichs und der Schweiz, Heft 6: 67—68. f. 5-6. 1915 
